1. Field of the Invention
The present invention relates to a drying machine or a drying machine with washing function that is capable of drying the laundry either in an exhausting fashion or in a condensing fashion. The present invention also relates to a method of controlling the same.
2. Description of the Related Art
Generally, a laundry drying machine is a machine that supplies dry hot wind, heated by a heater mounted in the laundry drying machine, into a laundry-receiving space, where clothes (hereinafter, referred to as “laundry”) are put, to dry the laundry. The laundry drying machine is classified into a drying machine that only dries the laundry and a drying machine with washing function that not only washes but also dries the laundry.
Also, the laundry drying machine is classified into an exhausting-type drying machine and a condensing-type drying machine.
In the exhausting-type drying machine, low-temperature air introduced through an open-type inlet duct is heated by a heater to obtain high-temperature and low-humidity air, and the high-temperature and low-humidity air is introduced into a drum. In the drum, heat exchange occurs between the high-temperature and low-humidity air introduced into the drum and the laundry put in the drum. As a result, the air is changed into middle-temperature and high-humidity air. The middle-temperature and high-humidity air is discharged out of the drying machine through an outlet duct.
In the exhausting-type drying machine as described above, the outlet duct is connected to an external duct, which is long and extends to the outside of a house where the drying machine is installed. If the external duct is disposed with high exhaust resistance, or the exhaust resistance is increased as different external ducts are connected to drying machines installed in houses, however, air flow rate is abruptly decreased, and therefore, drying time is increased. Also, high-temperature and low-humidity air is discharged out of the drying machine at the end of the drying operation with the result that energy efficiency of the exhausting-type drying machine is decreased.
In the condensing-type drying machine, high-temperature and low-humidity air heated by the heater is supplied into the drum, where heat exchange occurs between the high-temperature and low-humidity air and the laundry put in the drum. As a result, the air is changed into middle-temperature and high-humidity air. The middle-temperature and high-humidity air passes through a condenser, where heat exchange occurs between the middle-temperature and high-humidity air and the condenser. As a result, the air is changed into low-temperature and low-humidity air. The low-temperature and low-humidity air is heated again by the heater, and is then supplied into the drum. The air supplied into the drum is changed into middle-temperature and high-humidity air as described above. In this way, the air is repeatedly circulated to dry the laundry.
In the condensing-type drying machine, however, the size of a circulating channel is restricted when the circulating channel is formed. Also, the flow resistance is relatively large, and therefore, the air flow rate is decreased and the drying time is increased as compared to the exhausting-type drying machine.